Portable rubbing machine



Mmh 2o, 1951 s, A CROSBY ET AL 2,545,942

PORTABLE RUBBING MACHINE Filed Feb. '7, 1949 I 3 Sheets-Sheet 1 f j? a 45 i7 if? HIM): f 60 March 20, 1951 S. A. CROSBY ET AL PORTABLE RUBBING MACHINE 5 Sheets-Sheet 2 Filed Feb. 7, 1949 .All

March 20, 1951 s. A. cRosBY TAL 2,545,942

PORTABLE RUBBING MACHINE Filed Feb. 7, 1949 3 Sheets-Sheet 3 Patented Mar. 20, 1951 PORTABLE RUBBING MACHINE Stephen A. Crosby and Peter Zasadny, Chicago,

Ill., assignors, by mesne assignments, to Porter- Cahle Machine Company, Syracuse, N. Y., a corporation of New York Application February 7, 1949, Serial No. 74,924

l This invention relates to portable rubbing machines, and more particularly to small power provided with openings to receive ball-bearing driven sanders or polishing machines for use on various structural materials.

The primary object of the invention is to provide a portable rubbing machine which will reduce the physical fatigue and time required for various sander `and polishing operations.

Another object of the invention is to provide a portable rubbing machine where vibration is largely cancelled out by counterweights on opposite ends of the cranks which drive the polishing head.

Another object of the invention is to provide an improved blower which will draw air through a filter, cool the bearings of the machine and the housing of the motor, andY then be partially discharged so as to blow dust away from the machine. s

Still another object of the invention is to provide a housing which embraces the driving mechanism and has `a special suspension so that it may serve as a handle for the machine,

The invention is illustrated in a preferred embodiment in the accompanying drawings, in Which- Figure 1 is a top plan view of a machine embodying the invention; Fig. 2, an elevational view, partly in section showing the machine; Fig. 3, a front elevational view; Fig. 4, a Yvertical longitudinal sectional view, taken as indicated at 4-4 of Fig. 1; Fig. 5, a vertical sectional view, taken as indicated at line 5-5 of Fig. 4; Fig. 6, a fragmentary side elevational view of part of the device for securing the front section o f the housing to the main section; Fig. ,'7, a sectional view, taken as indicated at line 1-1 of Fig. 4; Fig. 8, a fragmentary elevational view of the rear portion of the machine, with the rear section of the housing partly withdrawn; Fig. 9, a plan viewl of one of thecranks with its lower counterweight; Fig. 10, an elevational view of the same; Fig. 11, a bottom plan view of the crank member; Fig. l2, a plan View of one of the auxiliary counterweights; Fig. 13, an elevational View of the same; and Fig. 14, a bottom plan view .of the auxiliary counterweights.

In the embodiment illustrated, A designates a main Supporting frame in which a horizontally.

disposed electric motor Vand fan B are mounted to rotate a pair of crank members C, which .in turn drive a rubbingpad .Dbeneath the machine; and E is a housing provided with a removable front section which contains an air lter F.

The supporting frame A has a hollow casting assemblies for the motor B and the cranks C.

The motor B has its shaft mounted in ballbearings I5 and its end portions are provided with bevel gears I6, to drive the cranks. Screws il anchor the motor eld ring into the motor frame.' The motor housing is provided at its iront end with an open front circular Cowling I8, held by screws I 8a. The Cowling surrounds an air fan E9 and greatly improves its efficiency in drawing air from the front of the machine and blowing it through the motor and rear portion of the machine. The crank members C are journalled in upper ball-bearing 29 and lower ballbearings 2l, the latter fitting around the central portion -22 of the cranks and being held in the supporting frame by a split ring 23 which snaps into an annular groove provided in the supporting frame. The cranks -C have splines 24. The front crank is provided with a bevel gear 25 surmounted by a spacing collar 26, while the rear crank has a bevel gear 2l which surmounts the rear spacing collar 28. Thus, both cranks are driven in the same direction by the bevel gears I6 on the motor shaft.

Auxiliary counterweights 29 are provided on the upper threaded ends of the crank shafts and are secured thereto by means of nuts 30. The lower ends of the crank shafts have bearing sockets which are offset gig of an inch from the l.v main axis of the crank shaft. An upper bearing ping and tensioning devices 3l, which are adapted 3l iS pressed into the socket and a lower ballbearing -32 is secured in position by a split ring The cranks are provided at their lower ends, opposite 'from the 'bearing sockets, with -a heavycounterweight 1313 which is diametrically opposite to the auxiliary top counterweight 29.

The rubbing pad D has top metal plates 35 to which a -felt pad 3B is cemented. The plates 35 are provided at each end with spring-held gripto grip the end portions of a .Strip of sand paper or polishing cloth which .is wrapped around the bottom and ends of the pad. The polishing head D is driven orbitally by a. pair of studs 33 which extend up into the bearings Y3 4 and -32 and have their lower ends secured to the plates 35 by means of plates 39 held by screws 46. Preferably, a strip of rubber or cushioning materialv 4I is interposed between the 'plates 39 and .the backing plates 3'5.

Preferably, the Ymain frame A is provided with cooling fins 42 around the crank bearings 20 and, 2i, The frame is also providedV with a centrally disposed rearwardly extending stud v43, and a pair of ears 44 for securing the rear section of the housing E to the frame.

The rear section 45 of the housing E has a socket 46 lined with an insulator bushing 41 to receive the stud 43. The upper inside of the rear section 45 has a pair of shoulders 48, which are drilled and tapped to receive socket head bolts 49 which grip the rear section of the housing to the main frame in a three-point suspension. The front section 50 separates from the rear section along an upwardly biased plane, and is provided with a pair of positioning studs 50a Which iit into holes provided in the rear section. Preferably, the portions of the front section and the supporting frame A, which are normally in contact, are coated with flock 5I, so that a substantially air-tight connection is made. The front portion of the supporting frame, as shown in Figs. 5 and 6, is provided with a pair of laterally extending studs 52, about which coiled ends of a spring wire bail 53 are snapped. A pair of ears 52a hold the wire in proper angular position to be engaged by a slot provided in the rear end of a headed screw 54 which is journalled in the front central portion of the front housing 50. A series of slots 55 are provided in the front section 50.

A removable thin foraminous filter member F is positioned inside of the slots 55, so that all of the air drawn into the machine by the fan I9 must pass through the removable filter. This prevents dust and abrasive material from being drawn into the machine. The rear section 45 of the housing also is provided with slots 55, so that part of the air that is drawn through the motor housing may be exhausted therethrough, while the remainder of the air is blown downwardly between the housing and the supporting frame and around the rear crank. This current of air blows the dust and abrasive material away from the edges of the pad D.

The housing E is provided with an opening 51 to permit access to the cap 58 covering the upper brush of the motor. The lower brush is covered by a cap 59 which extends through the bottom of the supporting frame and is accessible when the pad is removed from the machine.

Power is delivered to the machine from a wireV 60 which enters the rear section of the housing through a rubber sleeve 6|, and makes connection with a plug and socket 62. Wires 63 are connected to the motor through an oscillating switch 64 held by bolts 54a. The switch is provided with a downwardly extending actuator 65 which may be swung to oi or on position by a transverse bar 65 provided at its ends with fingers 6l of insulating material which project through openings in the rear section of the housing at the opening between the front and rear sections of the housing.

Operation of the machine, the operator can work on surf faces at practically any angle without difficulty.

The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, for some modifications will be obvious to those skilled in the art.

We claim:

1. A portabie rubbing machine comprising: a supporting frame, a horizontally disposed motor journalled in said frame and provided at its opposite ends with driving bevel gears, a pair of vertically disposed crank-members journalled in the frame and having bevel gears 'meshing with said driving gears so as to be driven in the same rotational direction by said motor, a driving head having its upper portions journalled in the lower portions of said crank-members for orbital movement with respect to said frame, and a housing embracing and secured to the supporting frame and forming a handle for the machine.

2. A machine as specified in claim 1, in which 3 the lower ends of the crank-members are provided with main counterweights opposite to the driving head journals, and the upper ends of said crank-members are provided with lighter auxiliary counterweights diametrically opposed to said main counterweights.

3. A machine as specied in claim l, in which the housing is formed in two sections, the rear section being secured to the supporting frame by a three point suspension, one point being at the rear of the frame and the other two spaced* points being near the top of the frame, and the front section of the housing being detachably secured to said rear section.

4. A machine as specified in claim 1, in which the housing is formed in two sections, the rear section being secured to the supporting frame frame, and the other two spaced points being bolts near the top of the frame, and the front section of said housing being detachably secured to said rear section.

5. A machine as specied in claim l, in whichV the motor is electric and is provided near its front end with a fan, and a perforate Cowlingy is provided around said fan so that air will be drawn through the front of the housing, around the front crank-member, blown through the,

motor casing and around the rear crank-member, and discharged partly through the rear of the housing and partly beneath the rear portion of said housing.

6. A machine as specified in claim 1, in which the motor is electric, the housing is formed in two separable sections, and a motor switch actu-. ator extends through said casing between said two sections.

STEPHEN A. CROSBY. PETER ZASADNY.

REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date 1,046,075 Kelley Dec. 3, 1912 2,247,993 Fisker July 1, 1941 A2,270,309 Kehle Jan, 20, 1942 2,367,668 Champayne Jan. 23, .1945. 2,395,537 Crosby Feb. 26, 1946i 

